


I Would Stay For You

by Malecforever88



Category: Shadowhunters (TV), The Mortal Instruments Series - Cassandra Clare
Genre: Anal Fingering, Anal Sex, Angst, Bottom Alec Lightwood, Bottom Magnus Bane, Demonic Possession, F/M, Fluff and Angst, Fluff and Smut, M/M, Malec, Rimming, Smut, Top Alec Lightwood, Top Magnus Bane, Will add tags as I think of them
Language: English
Status: In-Progress
Published: 2017-05-16
Updated: 2017-06-11
Packaged: 2018-11-01 08:31:05
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 3
Words: 3,518
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10918134
Author URL: https://archiveofourown.org/users/Malecforever88/pseuds/Malecforever88
Summary: Valentine is captured but the soul sword still hasn't been found. While the shadowhunter look for it, Alec and Magnus are building their relationship. Ever since they confessed their love things have been great. However, Magnus father has decided to make a move. He's bored and has to decided to put in motion his plan to expand his realm and Magnus will find out why Asmodeus went to all the trouble to conceive him.





	1. Chapter 1

It was just another night in the streets of New York City.  The vampires of the Hotel Dumort were waking from their slumber. Taki’s was in full swing and the Nephilim were out on patrol. It had been a few weeks since Valentine had been captured and the Clave was readying itself for his trial. Who knows why it was taking so long, but the Clave was good at one thing and that was it's bureaucracy. So it was just a matter of waiting. 

 

Alec, Isabelle, and Jace had just killed a few demons and were now heading back to the Institute. “Hey, I'm heading to Magnus’” Alec said. “It's fine. I can do the report.” Isabelle said with a smile. “ Are you sure?” Alex asked reluctantly. “Take some time for yourself Alec. Were all safe now” Isabelle answered. “Yeah, we can breath now. Go” Jace finally said with a half hearted smirk.  “Thanks” Alec said after hugging them goodbye. “I'll be home tomorrow. “No hurry. Mom is not coming back for a few days. Take your time. “ Isabelle waved as Alec head towards Magnus loft. 

 

As Alec walked he remembered the look on Jace’s face, making him feel a bit guilty.  Jace had found that he and Clary were, in fact, not brother and sister. But he hasn't told her after seeing her and Simon together. Alec knew it wasn't his fault, but he felt guilty for having such a happy relationship with Magnus, especially after they had confessed their love for each other. Lost in thought Alec made it to Magnus’ front door. Taking a relieved breath he opened the loft with the key that Magnus had given him weeks ago.  When he entered he found Magnus sleeping on the sofa with Chairman Moew sitting on his lap. Alec smiles to himself. Magnus always looks so breathtaking while he sleeps. Not that he isn't stunning the rest of the time. Quite the contrary.  But Alec loves seeing him with no makeup and sleeping. He looks so human. 

 

Not wanting to wake him, Alec quietly takes off his boots. Placing them by the door.  “Hello  Alexander” Magnus said with evidence of his sleep in his voice. Alec jumped up, startled by the sudden words, and looked over seeing Magnus smiling up at him from the sofa. Magnus sat up rubbing his eyes and stood walking over to Alec, pulling him into an embraced.  Alex rested his face in the crook of magnus' neck. Alex loved that Magnus was just barely taller than him. It allowed him to turn to puddy in his arms, which he did. All the tension, that he had carried from the Institute and the hunt, fell on to Magnus and Magnus gladly took it. 

 

“Long day?” Magnus hummed. “Yeah…” Alec whispered. “I'm sorry I'm getting demon ichor all over you…” he said with a frown. “Don't worry about it Dearly, we can always take a bath...how does that sound?” Magnus said, pulling away from Alec to look into his tired blue eyes. How Magnus loved those eyes.  They were the first thing he fell in love with on his nephilim. Alec nodding as Magnus pulled him to the bathroom.

 

Entering the bathroom Magnus pulled Alec toward his beautiful claw foot tub and after grabbing two fluffy towels he turned the hot water on. Alec began to undress, but Magnus stopped him. “Allow me” he said as he pulled Alec’s shirt shirt up. Alec lifted his arms to allow his shirt to be pulled off. Magnus then moved to take off his pants and his underwear, magically banishing the dirty clothes to the washer. 

 

Magnus then turned toward the tub and grabbed some of his oils to add to the water along with some bubbles. “That smells nice” Alec hummed feeling more tension leave me as he inhaled the aroma of sandalwood. Magnus turned the water off and began to undress. Once he was finished he climbed in the tub and pulled Alec with him, sitting down with his chest to Alecs bath. Alec relaxed against him with a pleased hum. “They still haven't put Valentine on trial yet…” Alec stated. “shh...not now my love, just enjoy this moment...no worries inside my home...just relax.” Magnus said as he stroked Alec’s hair. “okay” Alec groaned relaxing more against Magnus. “It's just about this at this moment” Magnus said kissing Alec on the shoulder. Magnus snapped his finger and his CD changer began to play.

 

_ It can be born anywhere _

_  
_ _ In the last place you'd expect _

_  
_ _ In a way you'd never dream _

 

 

“I love you” said Alec turning his head to pull Magnus into a kiss. 

_  
_ _ A single glance is all it takes _

_  
_ _ To get inside you _

 

“I love you too Alexander” Magnus said as he leaned in to kiss Alec deeply. 

 

_  
_ _ Love has a thousand stems _

_  
_ _ But only one flower _

 

\--------------------

 

Deep in the realm of Edom, Asmodeus watched his son and nephilim boy as they made love. 

 

“It’s  time for you to fulfil your purpose my son. I wonder if the boy will stand by you even then.” said with a grin that would put the Chester cat to shame. 

 

“I think it's time for me to expand our realm my love.”  he said, stroking the cheek of this queen, lilith, who sat upon his lap.

 

“Yes, my love, his body will fit you nicely. He is a pretty boy.”  replied lillth 

 

 

Asmodeus laughed and it echoed to the very core of Edom. 


	2. Chapter 2

**Summary for the Chapter:**

> Magnus and Alec have a domestic morning and then BAM demon attack. Etc

**Notes for the Chapter:**

> Sorry this took so long. Have artist things distracting me lol  
> Not beta read
> 
> Copyright belongs to Cassandra Clare 
> 
> Song:  
> Unsteady by X Ambassadors

The air was damp and thick. When Magnus opened his eyes he looked around and he found himself surrounded by an ominous fog that smelled of death. Barren hills

Stretched out as far as he could see and the air was thick with dust.  _ Edom.  _ Magnus had no idea how he'd gotten here, but he needed to get home and back to Alexander. 

 

Magnus started walking and he found himself approaching a figure silhouetted by robes. As he moved closer, he felt fear curling in his gut, but he kept moving. As Magnus came closer the figure turned to him. “Who are you?” he asked. “You don't recognize me son?” came a familiar voice.  _ Asmodeus _ . “Why have you brought me here?” Magnus said raging mixing with the fear. “Son, it's time to come home.”  Asmodeus said. “This is not my home, as I will Always be your” Magnus argued. “This will always be your home and I will always be your father. You have always been mine. And you always will be.” Asmodeus said pulling down the hood of his robes. Magnus gasp in horrible when he came face to face with himself. “You are me" Asmodeus smirked. The look-a-like’s hand rose and with a long claw slashed Magnus neck. Blood pooled around him at his feet. Magnus grabbed at his neck and the blood rose around him. Magnus choked and fought to get free, but the blood pulled him down and as everything went black a demented laugh filled his ears. 

 

“Magnus!”

 

Magnus screamed as he woke, thrashing around for something to grab on it. Two hands wrapped around his waist. And Alexander was in front of him. When Magnus realized who it was he went limp and fell on Alec, laying his head in the crock of his neck. Panting into his skin and shaking uncontrollably, Alec rubbed circles into his back to calm him, whispering words of love and security into Magnus’ ear.

 

Once he had calmed down he pulled away and looked at Alec, worried clear on his face. Magnus looked around and realized that the sun was rising over the horizon. It was morning “Magnus, are you okay?” he asked. “I'm sorry. I don't know what came over me” Magnus said

“It's okay. That nightmare seemed pretty bad. Do you want to talk about it?” Alec asked. “I…” Magnus started  “You don't have to” Alec said shyly. Magnus smiled at his nephilim. He was always so understanding, but Magnus knew he should tell him.

 

“I dreamed of Asmodeus. He had my face, Alexander.” Magnus said with a shudder. “Magnus you are not him.” Alec reassured. “ I know, but sometimes I wonder why he hasn't taken me yet. Why he went through all of that. Making my mother think he was her husband, Raping her. What was the point?” Magnus said, shaking once again. Alec wrapped his arms around the warlock and pulled him close. “I don't know. But I'm glad he did. I mean not the rape part…...but if he hadn't you wouldn't be here.” Alec said. Magnus smiled understanding what the boy was trying to say. 

 

“I love you.” Alec whispered, burying his face in Magnus hair. “I love you too.” They stayed like that for a few moments basking in each other’s scent. “ we should get up and have breakfast.” Magnus hummed. “Okay, I'll go make coffee and you go shower.” Alec said kissing Magnus forehead and climbing out of bed. Magnus got up and went into the bathroom and tried to wash away the nightmare. 

 

Walking out of the room, fully dressed, he found Alec in the kitchen holding a mug of coffee. “Here, drink up. I'm going to shower and then we can eat something.” Alec said. “What do you want Alexander?” Magnus purred leaning into Alec’s warmth. “Whatever you want.” Alec said leaving a kiss on the older man's cheek before he went into the bedroom. 

 

Magnus walked over to the table and snapped his fingers, summoning up a full breakfast of pancakes, eggs, and bacon from a diner down the street. Alec hated when Magnus used his magic for food, but Magnus just wasn't in mood for cooking. He left money knowing Alec wouldn't complain too much, since it wasn't stolen. 

 

Once Alec returned fully dressed, they sat down and ate. “You didn't steal this did you?” Alec asked narrowing his eyes. Magnus chuckled. “I left money and a tip, darling.” That seem to satisfy the Shadowhunter. He started eating. “I don't have to go to the Institute yet because Isabelle is doing the report. Do you have plans?” Alec asked. “No, we could just spend the day here lounging around.” Magnus said. They didn't get many days to do that so Magnus always took advantage of every opportunity. “Sure…” Alec started.

 

Before he could finish they both noticed the sky go dark through the window. “what the….”Alec said and then a portal opened in the middle of the room and Catarina walked through. “Magnus!” she yelled. Magnus knew Catarina was a very calm woman, so if she was yelling there was a problem. “What is it darling? What's wrong?” Magnus asked standing up and walking toward her. “Magnus there are demon portals opening all over the city and attacking mundanes. The hospital is getting overrun!” Alec stood up and walked to them. “Where?” he asked. “I will show you.” she said opening another portal. Alec ran and gathered his gear and followed the warlocks through. 

 

When they reached the other side, Magnus could see demons everywhere. They were attacking people left and right. Bodies were everywhere. Alec pulled out his phone and quickly send a text. “I just let Jace know, they should be on their way here.” Alec said readying his bow. Magnus summoned a ball of fire in his hand. Before they could move a demon ran at Magnus and he launched the fire ball. More demons ran at them. Alec killed a few, sending arrows flying as quickly as he could. Magnus was sending out magic in every direction, covering Alec’s back. He was so distracted,he didn't have time to avoid the claw that grabbed him. Magnus struggled against the demon, but it was no hope, two other demons had grabbed a hold of his hand, preventing him from using magic. 

 

_ Hold _

_ Hold on _

_ Hold on to me _

_ 'Cause I’m a little unsteady _

_ A little unsteady _

 

Alec turned and ran toward Magnus, but before he was able to reach him a dark cloud surrounded him, trapping him where he stood. The face of Asmodeus appeared out of the smoke. Alec struggled, but was unable to get out of the smoky prison.

 

_ Hold _

_ Hold on _

_ Hold on to me _

_ 'Cause I’m a little unsteady _

_ A little unsteady _

 

“Asmodeus, release him!” Magnus growled, still trying to get away from the demons holding him. “My son, calm yourself or I will kill him.” Asmodeus smirked. Magnus looked at Alec and then back at the demon prince. 

 

_ If you love me, don’t let go _

_ If you love me, don’t let go _

 

“Okay, just...don’t hurt him” Magnus said falling to his knees. “Good boy” Asmodeus said. With Alec still trapped by his magic, the demon prince walked out of the smoke, dressed in a white suit. He moved toward his son and kneeled. “You have always been my favorite son. You have never been broken, by Raziel and his children or by me.” Asmodeus said grabbing Magnus tightly by his chin. He tilted the warlock's face up and moved in closer. “It’s time for you to fulfill your purpose my son.” Asmodeus said.

 

_ Hold _

_ Hold on _

_ Hold on to me _

_ 'Cause I’m a little unsteady _

_ A little unsteady _

 

Fear filled Magnus. He didn’t know what was happening, but he could feel Asmodeus magic surround him. His skin tingled and he could feel the demon prince’s magic flow into his veins. “W-what a-are you doing?” Magnus stammered. 

  
  


_ If you love me, don’t let go _

_ If you love me, don’t let go _

_ Hold _

_ Hold on _

_ Hold on to me _

_ 'Cause I’m a little unsteady _

_ A little unsteady _

 

He wanted to struggle , but he couldn’t move. “It’s time for you to join me, my son. We will be one.” Asmodeus said. The last thing Magnus heard was Alec screaming his name and everything went black. 

 

_ Hold _

_ Hold on _

_ Hold on to me _

_ 'Cause I’m a little unsteady _

_ A little unsteady _

  
  


_ Alexander…. _

**Notes for the Chapter:**

> Drama!!!!! 
> 
> Oh shit! Wtf is Asmodeus doing >.> lol stay tuned...


	3. Chapter 3

**Summary for the Chapter:**

> Magnus isn't Magnus anymore, but he is. Alec won't let go.

**Notes for the Chapter:**

> Okay sorry guys for the delay. I've been doing business stuff and unfortunately that stuff takes priority. Hope you enjoy this. 
> 
> ~Not beta Read~

Alec POV

 

Alec felt his stomach twist and bile rise in his throat. Heard someone scream and he knew it was himself. He struggled against his restraints, but they would not budge. Tears filled his eyes and the only thing in his mind was Magnus. He had to get to him. He had to save him. All he could do was watch helplessly as Magnus and Asmodeus were enveloped by fire. “Alec!!” called a familiar voice. Alec didn’t respond, too focused on the scene before him. The fire died down and a figure emerged. Yellow cat eyes  burned within the figures silhouette.

 

Jace and Isabelle were running as Alec fell to the ground, being released by the smoky restraints. Alec landed on all fours and looked at the figure, not noticing as Jace and Isabelle came up behind him. The figured moved toward Alec. It was Magnus, but something was different. A sinister inhuman grin was plastered across his face. “Magnus…” Alec whispered confused and a little lost. Magnus started to laugh and it sent a shiver down Alec’s spine and not in a good way. “What…Magnus what is wrong with you.” Alec heard Isabelle say beside him. “Oh nothing Nephilim girl, i feel great. Haven’t felt this alive...well ever.” Magnus cackled. Alec started shaking

 

“Lilith, where are you?” Magnus said looking around. A woman came out from the shadows smiling sweetly at Magnus and moved to stand next to him. “What do you think?” Magnus asked spinning around with his arms up. “A little more glitter then I would like, but I suppose I could get use to it.” Lilith replied with a smirk. “WHAT THE HELL MAGNUS!” Jace yelled, looking lost himself. Magnus turned back to the three shadowhunters. “Haven’t you figured it out yet?” Magnus asked. “Warlock, why don’t you explain it to them.” Magnus looking at Catarina whose face was twisted in horror. “Asmodeus and Magnus are one.” Catarina said. “WHAT?! HOW!?” Isabelle yelled. Adrenaline coursed through Alec and he stood, “Get out of him now!” Alec said moving forward. 

 

The prince of hell  laughed “Oh Alexander, i don’t plan on doing that. I have waited years for him to grow into his power. Waited for him to ripen for me. He is the first of my offspring to have survived this long. Now it's time for him to serve his purpose.” Alec felt himself trembling with rage. “ I SAID GET OUT!” Alec yelled as he moved quickly toward Asmodeus. All of sudden he was knocked down with magic. When he sat up, he found lilith standing before him. “You do not touch him” she snarled raising her arm to strike him, magic sparking from her fingertips. Magnus’ hand caught her before she made contact. She looked over at Asmodeus surprised. “My love….” 

 

“Enough! We do not have time for this. Let us leave. Let the nephilim lick their wounds.” Asmodeus said, gripping her wrist tighter. “Don’t you want to kill them? A dead Nephilim is a good Nephilim. She said. Asmodeus let her wrist go with a Magnus flourish. “No.” was all he said. Lilith looked at him with even more shock, but backed away. Kneeling down in front of Alec. He leaned in so close Alec could feel his warm breath against his face. “Magnus is gone now. If I ever see you again I will kill you.” And then he kissed him. Alec being so shocked froze and before he could react Asmodeus was gone in a cloud of smoke. All the demons and lilith were also gone. 

 

_ Magnus _  Alec thought,  his vision blurred and before he blacked out he heard both Jace and Isabelle call his name, as Catarina ran to him. 

  
  


~~

 

Alec woke up with a pain in his back and head that told him, he was not at home with Magnus. As his vision cleared to a fully wakened state, everything that happened rush back to him. He sat up quickly and found himself in the infirmary. Catarina, Jace, and Isabelle were off to the side talking quietly. Isabelle glanced his way and realized he was awake and ran over time him hugging him tightly. “Oh my god, I’m so glad you’re okay.” she said, squeezing his shoulders. Jace came over and stood on the other side of Alec and patted his shoulder. “Good to see you awake.” Alec looked at his parabatai confused. He’d only been out for a little while. “Alec, you’ve been unconscious for two days.” Isabelle said with a sad smile. Alec’s eyes widen. “Two days?!” He looked up at Catarina, who had moved closer, as well, and she nodded. “I stayed here to make sure you were alright.” she said looking at him her age showing on her face(if that was even possible).

 

“I’m sorry…..” Alec felt bad that he had worried everyone and of course instead of being awake to find and save Magnus, they had to babysit him. Alec stood up. “We need to find Magnus.” Alec said moving toward the door. “What are we supposed to do once we find him?” Jace asked. Alec stopped. He didn’t know. He just knew he had to find him. “I don’t know….” Alec sighed. “ But we have to go” he started moving again only to be stopped by Catarina blocking the door. “Alec, Magnus is probably in Edom.” she said, “Okay, so portal us there.” Alec said getting annoyed by all the stalling. He just wanted Magnus back, “ Alec, we don’t even know how to get Asmodeus out of him. And I don’t think we can.” Catarina said.

 

Alec felt himself start to panic. “What to do you mean?!” he said breathing heavily now. “Asmodeus is a demon and demons possessed people. So he needs to be exorcised.” Alec finished, trying to stay calm. “We can’t. He didn’t just possesse him. He merged with him. Asmodeus and Magnus are one in the same now. At least they will be. Right now Asmodeus is strongest in him, but Magnus is there.” Catarina said sadly  “We can’t save him. There’s nothing we can do.” Alec felt his legs buckle under him and he fell to his knees. “No….Magnus….He can’t…” Alec whispered. A panic attack was forming just under the surface. 

 

Alec looked up and Jace was kneeling in front of him. “Alec, look at me and follow my breath….in and out…..in and out….in and out.” the blonde shadowhunter squeezed Alecs shoulders holding him steady. Grounding him the way only a parabatai could. Alec inhaled and exhaled and he started to calm. Now all he felt was sick. He pushed the nausea down and stood. “We have to try.” Alec said “I will not give up..I can’t lose him…” the last part mostly to himself. The other two shadowhunters and warlock nodded. “We might as well try.” Catarina said. Alec straightened himself and the four of them left the infirmary. 

 

_ Whatever it takes, I will be with him. Even if i have to go to hell and stay there.  _

  
_ Magnus...I’m never letting you go _

**Author's Note:**

> Hmmm? What is the bastard up to? :3
> 
> Song:  
> Love Exists By Amy Lee


End file.
